[Boost-users] [serialization] Please help me solve this compile error.

30 Jul 2014

      I am tearing my hair out over this, partly because I believe the code used
to compile.  I just can't see what the problem is. I enclose all the
pertinent code as I cannot say which bits are irrelevant.

There are two classes:
  ManagedArray which is an array of data without size or capacity data
(this is stored elsewhere).
 PersistentManagedArray which I wrote to enable ManagedArrays to be
serialized.

The error message is produced in 'main':
 error: no match for 'operator<<' in 'oa << PersistentManagedArray<int>((*
& size), (* & capacity), (* & ints))'

It seems to me that I have defined the necessary serialize member function
with the right signature.  Commented out is code I
wrote some time ago which used separate load and save functions.  This, I
believe, used to work.

#include <fstream>

#include <boost/archive/binary_oarchive.hpp>

#include <boost/archive/binary_iarchive.hpp>

#include <string>

using namespace std;

//****************************************************************************************************************************

template<class T>

class ManagedArray {

public:

  T *values;

  ManagedArray() {

    values = NULL;

  }

  ~ManagedArray() {

    if (values) {

      delete [] values;

    }

  }

  //Changes array size.  If array grows, the new values are unintialized.

  void resize(unsigned oldSize, unsigned newSize) {

    if (oldSize==newSize) return;

    T *newValues = (newSize==0) ? NULL : new T[newSize];

    if (oldSize!=0) {

      T *oldValue, *newValue;

      T *end = values + (oldSize<newSize ? oldSize : newSize);

      for(oldValue=values, newValue=newValues; oldValue<end;
oldValue++, newValue++) {

        *newValue = *oldValue;

      }

    }

    if (values) {

      delete [] values;

    }

    values = newValues;

  }

  //Changes array size.  If array grows, the new values are
initialised to copies of a prototype, initValue.

  void resize(unsigned oldSize, unsigned newSize, T &initValue) {

    if (oldSize==newSize) return;

    T *newValues = (newSize==0) ? NULL : new T[newSize];

    T *oldValue  = values;

    T *newValue  = newValues;

    if (oldSize!=0) {

      T *oldEnd = values + (oldSize<newSize ? oldSize : newSize);

      for(; oldValue<oldEnd; oldValue++, newValue++) {

        *newValue = *oldValue;

      }

    }

    T *newEnd = newValues + newSize;

    for(; newValue<newEnd; newValue++) {

      *newValue = initValue;

    }

    delete [] values;

    values = newValues;

  }

  inline T &operator[](unsigned index) {

    return values[index];

  }

  inline const T &operator[](unsigned index) const {

    return values[index];

  }

};

//****************************************************************************************************************************

//This class helps to save a ManagedArray in a Boost archive

// Usage:

//    ar & PersistentManagedArray(size, capacity, array);

template<class T>

class PersistentManagedArray {

public:

PersistentManagedArray(unsigned &size, unsigned &capacity,
ManagedArray<T> &managedArray) :

    _size(size),

    _capacity(capacity),

    _managedArray(managedArray) {valueArrayExists =
(_managedArray.values!=NULL);}

private:

  unsigned        &_size;

  unsigned        &_capacity;

  ManagedArray<T> &_managedArray;

  bool            valueArrayExists;

  friend class boost::serialization::access;

//  template<class Archive>

//  void save(Archive & ar, const unsigned int version) const {

//    ar & valueArrayExists;

//    if (valueArrayExists) {

//      for(unsigned i=0; i<_size; i++) {

//        ar & _managedArray.values[i];

//      }

//    }

//  }

//  template<class Archive>

//  void load(Archive & ar, const unsigned int version) {

//    _managedArray.values = NULL;

//    ar & valueArrayExists;

//    if (valueArrayExists) {

//      _managedArray.resize(0, _capacity);

//      for(unsigned i=0; i<_size; i++) {

//        ar & _managedArray.values[i];

//      }

//    }

//  }

//  BOOST_SERIALIZATION_SPLIT_MEMBER()

  template<class Archive>

  void serialize(Archive & ar, const unsigned int version) {

    ar & valueArrayExists;

    ar & _size;

    ar & _capacity;

    if (Archive::is_loading::value) {

      delete _managedArray.values;

      _managedArray.values = new T[_capacity];

    }

    for(unsigned i=0; i<_size; i++) {

      ar & _managedArray.values[i];

    }

  }

};

int main(int argc, char *argv[]) {

  ManagedArray<int> ints;

  unsigned    size;

  unsigned    capacity;

  string fileName = "data.xxx";

  ofstream file(fileName.c_str(), ios::out|ios::binary);

  if (file.good()) {

    boost::archive::binary_oarchive oa(file);

    oa << PersistentManagedArray<int>(size, capacity, ints); //This
line does not compile !

  }

}

[Boost-users] [serialization] Please help me solve this compile error.

Paul Blampspied